Cigarette smoke is a major, but preventable, cause of lung cancer. Chemical carcinogenesis is a multistage process involving initiation, promotion and progression, in which initiation is the critical first step. Initiation requires the binding of active chemical carcinogens to genomic DNA, forming DNA adducts resulting in mutation and consequent cancer.

The detection and quantification of DNA adducts are therefore important and essential early indicators of cancer risk. The major carcinogens in tobacco smoke are polycyclic aromatic hydrocarbons such as benzo(a)pyrene. Levels of smoking-related aromatic DNA adducts decrease on cessation of smoking and are positively correlated with the number of packs of cigarettes smoked per year. The variance in aromatic DNA adduct patterns and levels in peripheral blood lymphocytes of smokers before and after preventative strategies are thus good surrogate biomarkers for evaluating the ability of preventive agents to reduce DNA damage and, thus, cancer risk.

Morinda citrifolia (noni) is a traditional tropical folk medicine that has been used by Polynesians for more than 2000 years. It is thought to have a broad range of health and nutritional benefits including preventive properties. Noni intake has been linked with reductions in blood pressure and joint swelling, cessation of internal and external infection, and preventing growth of precancer cells. Tahitian noni juice (a blend of noni with lesser amounts of blueberry and grape juices) has strong antioxidant, anti-inflammatory, antiangiogenic and antiproliferative activities. It has also been shown to significantly reduce the aromatic carcinogen dimethylbenzo(a)anthracene and its induced mammary carcinogenesis.

A study by Wang et al.¹, evaluated the impact of Tahitian noni juice (TNJ) on aromatic DNA adducts of peripheral blood lymphocytes in 203 smokers, before and after a 1-month intervention. Aromatic DNA adduct levels in all participants were reduced by 49.7% and 37.6% in the groups receiving 1 oz and 4 oz TNJ, with a more positive impact found in male smokers as compared with that in female smokers. The results suggest that drinking 1--4 oz TNJ daily may reduce the risk of cancer in heavy smokers by blocking carcinogen-DNA binding or eliminating DNA adducts from genomic DNA.
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1 Wang, M-Y; Peng, L; Lutfiyya, MN; Henley, E; Weidenbacher-Hoper, V; Anderson, G (2009). Morinda citrifolia (noni) reduces cancer risk in current smokers by decreasing aromatic DNA adducts. Nutrition and Cancer 61 (5) 634-639.

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